Is It Wrong to Pick Up Girls in A Dungeon? (ダンジョンに出会いを求めるのは間違っているだろうか, Dungeon ni Deai wo Motomeru no wa Machigatteiru Darou ka?) is a Japanese Light Novel series written by Fujino Omori, with illustrations by Suzuhito Yasuda. It published by GA Bunko, an imprint SB Creative. The novels have received a manga and 4-koma adaptation serialized in the Gangan Joker and Gangan Online magazines respectively in 2013, which have, in total, been compiled into five volumes. During the 2015 Spring Season the series received an anime adaptation by J.C.Staff, spanning thirteen episodes (April 4, 2015 to June 27, 2015). An OVA premiered on December 7, 2016. A spin-off anime adaptation also by J.C.Staff, Dungeon ni Deai wo Motomeru no wa Machigatteiru Darou ka Gaiden: Sword Oratoria (Sword Oratoria: Is it Wrong to Try to Pick Up Girls in a Dungeon? On the Side), premiered on April 15, 2017 and ran for 12 episodes to July 1, 2017. A 2nd season of the main storyline and a movie, Orion no Ya (Arrow of the Orion), were announced on February 18, 2018.[1] The movie will premiere some time in 2019.[2]

The series is often shorted to DanMachi (ダンまち); the "Dan" from Dan-jon/Dungeon (ダンジョン) and the "Machi" from Machi-gatteiru (間違っている).

Commonly known as the "Dungeon," the city of Orario possesses a huge labyrinth in the underground. Its strange name attracts excitement, illusions of honor, and hopes of romance with a pretty girl. In this city of dreams and desires, new adventurer Bell Cranel has his fateful encounter with the tiny Goddess Hestia.

Thus begins the story of a boy striving to become the best adventurer and a lonely goddess searching for followers both working together to fulfill their goals. (Via MyAnimeList.net)